INTRO(7) Device and Network Interfaces INTRO(7)


Intro, intro - introduction to special files


This section describes various device and network interfaces available
on the system. The types of interfaces described include character and
block devices, STREAMS modules, network protocols, file systems, and
ioctl requests for driver subsystems and classes.

This section contains the following major collections:

The system provides drivers for a variety of hardware devices,
such as disk, magnetic tapes, serial communication lines, mice,
and frame buffers, as well as virtual devices such as pseudo-
terminals and windows.

This section describes special files that refer to specific
hardware peripherals and device drivers. STREAMS device
drivers are also described. Characteristics of both the
hardware device and the corresponding device driver are
discussed where applicable.

An application accesses a device through that device's special
file. This section specifies the device special file to be used
to access the device as well as application programming
interface (API) information relevant to the use of the device

All device special files are located under the /devices
directory. The /devices directory hierarchy attempts to mirror
the hierarchy of system busses, controllers, and devices
configured on the system. Logical device names for special
files in /devices are located under the /dev directory.
Although not every special file under /devices will have a
corresponding logical entry under /dev, whenever possible, an
application should reference a device using the logical name
for the device. Logical device names are listed in the FILES
section of the page for the device in question.

This section also describes driver configuration where
applicable. Many device drivers have a driver configuration file
of the form driver_name.conf associated with them (see
driver.conf(4)). The configuration information stored in the
driver configuration file is used to configure the driver and
the device. Driver configuration files are located in
/kernel/drv and /usr/kernel/drv. Driver configuration files for
platform dependent drivers are located in /platform/`uname
-i`/kernel/drv where `uname -i` is the output of the uname(1)
command with the -i option.

Some driver configuration files may contain user configurable
properties. Changes in a driver's configuration file will not
take effect until the system is rebooted or the driver has been
removed and re-added (see rem_drv(1M) and add_drv(1M)).

This section describes the programmatic interface for several
file systems supported by SunOS.

This section describes ioctl requests which apply to a class of
drivers or subsystems. For example, ioctl requests which apply
to most tape devices are discussed in mtio(7I). Ioctl requests
relevant to only a specific device are described on the man page
for that device. The page for the device in question should
still be examined for exceptions to the ioctls listed in section

This section describes STREAMS modules. Note that STREAMS
drivers are discussed in section 7D. streamio(7I) contains a
list of ioctl requests used to manipulate STREAMS modules and
interface with the STREAMS framework. Ioctl requests specific
to a STREAMS module will be discussed on the man page for that

This section describes various network protocols available in

SunOS supports both socket-based and STREAMS-based network
communications. The Internet protocol family, described in
inet(7P), is the primary protocol family supported by SunOS,
although the system can support a number of others. The raw
interface provides low-level services, such as packet
fragmentation and reassembly, routing, addressing, and basic
transport for socket-based implementations. Facilities for
communicating using an Internet-family protocol are generally
accessed by specifying the AF_INET address family when binding a
socket; see socket(3SOCKET) for details.

Major protocols in the Internet family include:

o The Internet Protocol (IP) itself, which supports the
universal datagram format, as described in ip(7P).
This is the default protocol for SOCK_RAW type
sockets within the AF_INET domain.

o The Transmission Control Protocol (TCP); see tcp(7P).
This is the default protocol for SOCK_STREAM type

o The User Datagram Protocol (UDP); see udp(7P). This
is the default protocol for SOCK_DGRAM type sockets.

o The Address Resolution Protocol (ARP); see arp(7P).

o The Internet Control Message Protocol (ICMP); see


add_drv(1M), rem_drv(1M), Intro(3), ioctl(2), socket(3SOCKET),
driver.conf(4), arp(7P), icmp(7P), inet(7P), ip(7P), mtio(7I), st(7D),
streamio(7I), tcp(7P), udp(7P)

System Administration Guide: IP Services

STREAMS Programming Guide

Writing Device Drivers

September 29, 1994 INTRO(7)